European patent application no. 0340978 A2 describes a modulator/demodulator device which comprises three modules. The first module performs a function of echo canceler on received samples. The second module performs a function of demodulation on samples that are transmitted thereto by the first module. Finally, the third module acts as a controller. It triggers the operations of the first and second module, and it serves as an intermediary for the exchanges of data, notably from the first module to the second module. It is also this third module that receives the data delivered by the second module so as to relay them to user modules.